1. Field of Invention
This invention generally relates to a dispenser for fluids that will need some pumping action to let the fluid inside a container exit without difficulty, but at the same time will impede the entrance of other substances like air, water and dirt into the container and pump.
2. Prior Art
Previously all dispensers were made using expensive springs, ball metallic valves, and some kind of piston system or propellants to pump the fluid from a container to the exterior using an actuator that the user needs to press in order to activate pumping action. Included in these devices are aerosols that are often used by normal people for cosmetic and medical applications. These devices are consumed in big quantities and are becoming a problem because they take up space in landfills and because the propellants that are used on them are affecting climate change and are responsible for some greenhouse emissions. Many countries still allow these propellants to be used, including the U.S. (e.g. propellant 134A banned in Europe but permitted in the U.S.). According to the U.S. government they will be eliminated in the next 10 to 15 years. Many of the components used in these devices are metallic, e.g., aluminum, steel, chrome, lead. Some of these metals, such as aluminum and steel, can be recycled. However, others are harder and contaminate the environment, such as chrome and lead.
The use of current aerosol dispensing devices cannot continue and new devices that provide the same function and are recyclable should be developed. One of the problems is to keep the product inside these devices from getting contaminated, a task that is easily accomplished when using an aerosol. For the reasons detailed above, aerosols will be off the market one day. This is the reason why we need to find other ways to dispense fluid or fluid like substances well from a device that is cheaper, recyclable and will not harm the atmosphere with its emissions when put in the trash.
Some of the new dispensers are more environmentally-friendly but will leave the fluid inside the pump open to any kind of contamination getting inside the container. Some inventors have started to solve this problem, adding a closeable lid that the user must insert on the nozzle to close and to prevent any extraneous fluids or particle(s) from entering inside the pump and container. Sometimes this works well enough. However, in some cases, such as creams that can easily get oxidized with air and reduce their potency, this situation becomes critical. At the same time, some fluids used in medical applications need to stay clean and free of contaminants to be safe to use for human applications. All the dispensers heretofore known in the market suffer from a number of disadvantages:                (a) All dispensers currently available in the market allow air to enter in the pump and container. This can result in oxidation of the substance inside the container. The substance will get damaged or change its properties over time. An example would be an anti-age cream with certain vitamins that in contact with air will change color, thicken and oxidize, losing their anti-aging properties. Another example is a cream that helps to heal scars, but is not effective if put into contact with oxygen. These creams are usually very expensive.        (b) On a normal dispenser, any contaminants coming from the exterior can enter the container through the pump, contaminating and damaging the formula of a medical product. This is especially critical in medical applications where bacteria or other microorganisms can enter the container and grow inside. Later the patient who is taking this formula can get infected by the bacteria or other microorganisms. This can happen to patients with a low immune system, who can die from an airborne disease coming from the container that has the medicine that is supposed to cure them, not infect them.        (c) The dispenser needs to have the nozzle closed with a lid to prevent any contaminant from entering the container. Sometimes people do not like to close the nozzle, forget or do not have time to do it. For example, when dispensing a diaper rash cream, if the baby moves around all the time, it is easy to forget to close the cream while putting a diaper on the baby after using the cream.        (d) Using a dispenser for many applications create a large amount of trash when the dispenser is discarded after the product inside is used. This is especially noticeable when these devices are used for cosmetic and especially medical applications where they are mass-produced. These devices cannot be degraded or recycled easily, creating a problem for the environment.        (e) Current dispensers are more expensive and use expensive components as steel springs and expensive plastics to work properly.        
3. Object and Advantages
Accordingly several objects and advantages of the invention are:                (a) To provide a dispenser that will pump and act as a check valve when dispensing the product inside. The dispenser allows the product; usually a fluid or cream, to exit, but at the same time does not permit the entrance of air, water, bacteria, microorganisms, dirt and other undesirable substances inside the container.        (b) To provide a dispenser that can dispense a metered amount of fluid that can be useful for certain medical applications where dispensing a dose is critical.        (c) To provide a dispenser that seals itself, so that no harm will come to the contents of the container if the device is in a dirty environment.        (d) To provide a dispenser that can easily be injection molded and manufactured very easily, with only a few components.        (e) This dispenser can be made of plastics like polypropylene, polyethylene, and thermoplastics elastomers like Santoprene™ materials that are easily recyclable.        (f) To provide a dispenser that can be set ready to dispense with just one push and that will close automatically to prevent any spill.        
Further objects and advantages will become apparent from a consideration of the ensuring description and drawings.